Heat resistant covering



De 11, 1951 M. L. loNlDL-:s Erm. 2,578,188

HEAT RESISTANT COVERING Filed April 1s, 194e @iff I Patented Dec. 11, 1951 HEAT RESISTANT COVERING Margaret L. Ionides, deceased, late of `Silver Spring, Md., by Hewitt Cochran, executor, Washington, D. C., and Paul A. Siple, Arlington, Ya.

Application Alll'ls, 1948, Serial N0. 21,518

l. Claims. (Cl. k-28) (Granted under the act of March 3, 1883, al amended April 30, 1928; 370 0. G. 757) 1 The invention described herein, if patented.

Kmay be manufactured and used by or for the Goverment for governmental purposes, without the payment to us of any royalty thereon.

l Our invention relates to a method of protecting the human body or inanimate bodies or objects from external heat of high degree and to a material for that purpose which is of laminated construction and is particularly suitable for use in making heat resistant garments.

This application is a continuation-impart of application Serial No. 556,646, Margaret L. Ionides (now deceased) and Paul A. Siple, filed September 30, 1944, now abandoned.

In the past it has been the practice to construct heat resistant garments for the human body or its members, and coverings for other objects and bodies of all kinds from composite fabrics or materials all of which include an outer covering of non-combustible material of low thermal conductivity or a material treated to make it noncombustible. The protection afforded by coverings constructed of these materials is limited, particularly in the case of garments for the protection of the human body or its members, because the material must be relatively thin in order to retain sufllcient flexibility to make it suitable for such use and, therefore, heat is soon conducted through the fabric to the interior of the covering. Even though the exterior heat conducted through these fabrics is nothigh enough to make a garment unbearably hot, nevertheless,

, it is uncomfortable to wear not only because of i invention to provide a new and improved method ofy protecting against external heat of high degree in which external heat is carried away from the immediate vicinity of the area to be protected and is dissipated to the surroundings.

Another object of the present invention is the provision of a new and improved material of 1aminated construction for use in making garments or other coverings for protecting against high temperatures, which may readily be formed into completed garments or body coverings, and which will be flexible and compact so that when made into garments movement by the wearer is not unduly restricted. y

Another objectof the yinvention is the provision of a new and improved material for use in thel construction of heat resistant garments and body coverings which is light in weight, readily fabricated from inexpensive material, and which is durable and fully effective to perform its intended be protected and arranging them in a predetermined order on the body or body member to' provide an outer absorbent layer separated from a thermal-insulating lining layer.

The protection aorded byreproof'suits and garments or other coverings as they are manufactured at present is limited because there is no way of preventing heat from being conducted in a relatively short time to the inner layer or layers of material. They soon become toohot to provide the protection desired in spiteof the fact that they are made of non-combustible materials having lowheat conductivity, such as asbestos. and if the heat or flame encountered is concentrated in a relatively small area, a burn will almost certainly result in the area underlying' the spot where this direct flame impinges on the covering. Constructing protective fabrics of thicker material does not remedy this defect because it only prolongs, for a short period. the time needed for the heat to be conducted through it. Furthermora'if a garment is made from this fabric, it tends to become so bulky and inflexible that movement of the wearer is unduly restricted. There is a practical limit to the thickness of the material out of which garments such as gloves may be constructed. In adidtion to the above defects, all garments constructed from the fireproof materials commonly used today are extremely uncomfortable to wear for any length vof time because they become warm not only from the outside, but also from the heat of the body I inside the garment. There is no way of prevent- 3 Ing this from happening or of dissipating this heat or cooling the inside of the garment.

To overcome these disadvantages of the prior art, the present invention provides a new method for protecting against external heat. and for the construction of heat resistant garments and other coverings, which makes use of a vaporizable agent absorbed in the outer layer of the heat resistant garment or covering i'or absorbing heat while'being vaporized, and in vaporized form. carrying it outwardly from the garment. A suitable agent is one that is vaporizable at a relatively low temperature and has a high heat of vaporization so that a great deal of heat is absorbed while it is vaporizing. Water is an ideal agent for this purpose because water at 100 C. absorbers 539 calories of heat per gram in being vaporized to water vapor at the same temperature in addition to the heat it has absorbed in being raised to 100 C. It is also true that water is a good conductor of heat. therefore, soaking of the present heat resistant garments or coverings in water only tencia to lessen their heat resistant properties. However, by the application of water to selected layers of a garment or coverings, at the same time maintaining the other layers dry. and preventing transfer of vapor thereto, it has been found that increased protection against heat is obtained.

The accompanying drawings show by way of illustration: y

In Figure 1 a cross-section. broken away, through a. heat-protective garment in accordance with the present invention;

In Figure 2 a cross-section, broken away, through a modified heat-protective garmentin accordance with the present invention; and

In Figure 3 a perspective view. partly broken away. of a heat-protective glove incorporating the principles of the present invention.

Gloves are only one of the applications in which the principle of our invention may be advantageously applied. It will be obvious that the same method of construction may be used for other types of garments and all kinds of body coverings which are to be used to afford protection against heat, particularly when they are intended for use where the heat is intense and the time of exposure relatively short.

Alaminated material for making a garment in accordance with the present invention is divided into three dinerent portions or layers. The first layer l which forms the lining or inner side of a nished body covering consists of an absorbent material of low heat conductivity preferably non-combustible. This lining may consist of a single layer of material of sufficient thickness to provide the desired amount of thermal insulation 4 as shown in Figure 2, or it may be made up from one or more laminations of material as shown in Figure l. Laminations of glass fiber cloth are suitable for this purpose; but other fire-resistant materials, such as wool, impregnated with a, fireresistance imparting solution (e. g., an aqueous solution of monosodium phosphate, disodium phosphate and borax as set forth in U. S. Patent No. 1,501,985), may be used. 'I'he first layer of material is completely overlaid by a second layer II of water and water vapor impermeable material. Materials such as rubber-like polyvinyl plastics, nylon sheeting, or any of the synthetic rubbers or plastics which are flexible enough to be made into clothing are suitable for this purpose. provided they are impermeable to both water and water vapor. this being essential to the proper functioning of the covering. Over this is placed an outer layer l2 of any material which has low heat conductivity and is capable of absorbing relatively large quantities of water. and which consists either of a single layer of suilicient thickness as shown in Figure 2 or laminations as shown in Figure 1. Certain glass ber cloth has been found to be effective if this outer layer is to be of laminated construction but any fire-resistant thermal insulating material preferably, but not necessarily, non-combustible and capable of absorbing relatively large quantities of water will be suitable. The glass fiber cloth used in the inner and outer layersis made in various weights, so that it is possible to select laminations of the proper weight to provide a material suitable for the degree of heat expected to be encountered. The laminations of material in each of the layers may be basted, stitched or secured together in any other suitable fashion and the three separate layers stitched, basted or otherwise secured together to form the completed material from which the protective garments of various types are fabricated.

The thickness of the layers of which a heatresistant garment in accordance with the present invention is composed may vary in accordance with the materials used and in accordance with the requirements which the garment will be called upon to fulfill. For instance, the inner thermally insulating layer (I0 in Fig. 2; I3 in Fig. 3) may be V4" thickness of wool; the fluid impermeable intermediate layer (II in Fig. 2; I4 in Fig. 3) may be of a 115 thickness of polyvinyl plastic or nylon sheeting; and the outer fire-resistant and liquid-absorbent layer (I2 in Fig. 2; I5 in Fig. 3) may be a 1/2" thickness of glass ber fabric. These figures may, of course. be varied; however.

the greater the thickness of the inner and outer layer the greater the weight to be carried by the user, which will offset wholly or in part the advantage of greater heat insulation and liquidretentivity afforded by thicker layers.

The inner layer of a hood, cape, trousers, or glove made in accordance with the present invention conforms in shape to the body portion to be protected and is completely surrounded by the intermediate fluid-impermeable layer, which in turn is completely surrounded by the outer fire-resistant water layer.

Before that a protective garment, constructed from the material above described, is used, the outer layer I2 is saturated with water. The garment is then ready to be used, and when heat is encountered it is absorbed by the water in the outer layer I2, and as the Water vaporizes it passes into the atmosphere and carries with it the heat which was absorbed in its vaporization. and this is dissipated to the surroundings. In this way large quantities of heat are removed from the outer layer of the garment, and as long as it remains moist its temperature will not exceed C. The impermeable layer of material I I prevents the water or water vapor from traveling inwardly, and the inner layer of material having a low conductivity prevents the small amount of heat that does reach it from being conducted inwardly to the covered body, so that ample protection is afforded against hot spots that may develop in the outer layer of the garment. Thus, as long as there is vaporizable water absorbed in the outer layer, the heat conducted to the intermediate layer and the outermost region of the inner layer cannot exceed 100 C.; the thermally insulating properties of the inner layer further reduce this heat to the order of about 60 C. at

its innermost region nearest the body. The latter temperature, while far from comfortable, is not intolerable and not damaging to the human skin during a period of exposure which is not unduly prolonged.

If the heat is very intense, or the period of exposure is long, so that there is a likelihood oi' a great deal of water in the garment or covering being vaporized, water from a hose may be played on the covering from a distance to replenish the water in the outer layer.

In certain cases, for example, where a particular object or only a particular member of the body. such as a hand, is to be protected it may be advisable, instead of making a complete garment from material as above described. to make up from appropriate materials separate individual coverings conforming to the shape of that object or body member and of a size sunlcient to ilt one over the other. Thus, if it is desired to provide a protective glove for handling hot objects, a separate glove I3 of wool or any lining material, a second glove I4 of water and vapor impermeable material and a third glove I5 of thermal-insulating water-absorbent material are made vup of a size suiiicient to flt one over the other in the proper order. The gloves are placed on the hand, the lining glove I3 being placed on ilrst, then the impermeable glove I4 and lastly the absorbent glove I5 which, either before or after placing on the hand, is soaked in water. If, after a period of use, the outer glove begins to dry it may again be soaked in water, and it will again and immediately be fully eiective. This method of protecting the hands or feet and other parts of the body is particularly advantageous for such applications because if only a part of the garment, such as the outer absorbent covering, wears out it may be discarded and a new outer covering substituted, whereupon the glove is as good as new. `By using this method the cost of repair and replacement is greatly reduced without impairing the utility or effectiveness ofthe garment or interrupting the period of its use. The relative thicknesses of glove layers I3, I4, and I5, may substantially correspond to those of layers I0. II,and I2. g

Instead of providing three separate superimposed gloves, an inner glove of wool or other thermally insulating material may be combined with an outer laminated glove, which outer glove consists of a layer of fluid-impermeable material to which is secured an outer layer of water absorbent lire-resistant material such as glass ilber fabric. Or the inner glove shell may be laminated with an inner layer of wool to which is secured a layer of iiuid impermeable material; and a separate outer glove of glass liber fabric or other fireresistant and water absorbent material lits over such inner glove.

The above method of providing 'protection against heat cannot be applied with the present garments or other protective coverings because water is such a good conductor of heat that when they are soaked in water, heat is so much more rapidly conducted from the exterior to the interior of the garment or covering that they lose, ratherthan gain, in resistance to heat. This is true because these garments and coverings do not include an impermeable layer and without this layer of water from the outer surface soaks through to the inner lining layers. Heat and hot vapor are then able to travel inwardly from the exterior to the inner surface of such garments or 6 coverings without hindrance, thereby greatly lessening the protection they ailord. y

While the principle of the invention has been described more or less specifically as applied to 5 gloves, it will be obvious that this same method may be applied in the fabrication of coverings of all kinds for the protection of bodies. Having thus described the invention, what we claim as new and desire to secure by Letters Patent is as follows:

l. An article of wearing apparel for protecting a re-ghters body or body member by evaporative dissipation of intense external heat, said article of wearing apparel comprising a plurality of ilexible layers conforming to the shape of said body or body member and arranged one over the other, and including a ,thermally insulating inner layer of low heat conductivity, an intermediate layer of duid-impermeable material completely enclosing said inner layer, and a lire-resistant liquid-absorbent outer layer of low heat conductivity completely enclosing said intermediate layer. said outer layer being of substantial thickness exceeding the thickness of either of said inner and intermediate layers, so as to retain a large quantity of a vaporizable coolant liquid having a high heat of vaporization for dissipating external heat when said liquid is heated beyond its boiling point and for maintaining the temperature of said outer layer at a point not exceeding the boiling point of said liquid until said liquid is completely vapcrized, said intermediate and said iner layers being in cooperativev relation with said outer layer to shield said body or body member from hot vapors and from conductive heat transfer.

2. An article of wearing apparel for protecting a fire-fighters body or body member by evaporative dissipation of intense external heat, said article of wearing apparel comprising a plurality of flexible layers conforming to the shape of said body or body member and arranged one over the other, and including a thermally insulating inner layer of low heat conductivity, an intermediate T layer of fluid-impermeable material completely enclosing said inner layer, and a fire-resistant liquid-absorbent laminated outer layer of low heat conductivity completely enclosing 'said intermediate layer, said outer laminated layer being of substantial thickness exceeding the thickness of either of said inner and intermediate layers. so as to retain a large quantity of a vaporizable coolant liquid having a high heat of vaporization for dissipating external heat when said liquid is heated beyond its boiling point and for maintaining the temperature of said outer layer at a point not exceeding the boiling point of said liquid until said liquid is completely vaporized, said intermediate and said inner layers being in cooper- 00 ative relation with said outer layer to shield said body or body member from hot vapors and from conductive heat transfer.

3. An article of wearing apparel forprotecting a re-iighter's body or body member by evapora- 35 tive dissipation of intense external heat, said article o'f wearing apparel comprising a plurality of ilexible layers conforming to the shape of said body or body member and arranged one over the other, and including a thermally insulating lam- 70 lnated inner layer of low heat conductivity, an intermediate layer of fluid-impermeable material completely enclosing said inner layer, and a iireresistant liquid-absorbent laminated outer layer of low heat conductivity completely enclosing said 75 intermediate layer, said outer laminated layer being of substantial thickness exceeding the thickness of either of said inner and intermediate layers, so as to retain a large quantity o a vaporizable coolant liquid having a high heat of vaporization for dissipating external heat when said liquid is heated beyond its boiling point and for main taining the temperature of said outer layer at a point not exceeding the boiling point of sai liquid until said liquid is completely vaporized, said intermediate and said inner layers being in cooperative relation with said outer layer to shield said body or body member from hot vapors and from conductive heat transfer.

4. An article of wearing apparel for protecting a re-ghter's body or body member by evaporative dissipation of intense external heat, said article of wearing apparel comprising a plurality of flexible layers conforming-to the shape of said body or body member and arranged one over the other, and including a thermally insulating inner layer of low heat conductivity, an intermediate layer of fluid-impermeable material completely enclosing said inner layer, and a non-infiammable liquid-absorbent outer layer of glass-fiber fabric completely enclosing said intermediate layer, said outer layer being of substantial thickness exceeding the thickness of either of said inner and intermediate layers, so as to retain a large quantity of a vaporizable coolant liquid having a high heat of vaporization for dissipating external heat when said liquid is heated beyond its boiling point and for maintaining the temperature of said outer layer at a point not exceeding the boiling point of said liquid until said liquid is completely vaporized, said intermediate and said inner layers being in cooperative relation with said outer layer to shield said body or body member from hot vapors and from conductive heat transfer.

5. An article of wearing apparel for protecting a re-flghters body or body member by evaporative dissipation of intense external heat, said article of Wearing apparel comprising a plurality of flexible layers conforming to the shape of said body or body member and arranged one over the other, and including a thermally insulating inner layer of low heat conductivity, an intermediate layer of fluid-impermeable material completely enclosing said inner layer, and a non-innammable liquid-absorbent outer layer of laminated glass-fiber fabric completely enclosing said intermediate layer, said outer layer being of substantial thickness exceeding the thickness of either of said inner and intermediate layers, so as to retain a large quantity of a vaporizable coolant liquid having a high heat of vaporization for dissipating external heat when said liquid is heated beyond its boiling point and for maintaining the temperature of said outer layer at a point not exceeding the boiling point of said liquid until said liquid is completely vaporized, said intermediate and said inner layers being in cooperative relation with said outer layer to shield said body or body member from hot vapors and from conductive heat transfer.

6. The method of shielding a member of the human body against intense external heat, comprising placing over said body member an inner layer of thermally insulating material substantially corresponding in shape to said body member. then completely enclosing said inner layer with a layer of fluid-impermeable flexible material of a shape corresponding to the shape of said inner layer, then completely enclosing said duid-impermeable layer with a thick ilexible outer layer of nre-resistant liquid-absorbentJ material, the thickness-of said outer layer exceeding the thickness of either of said inner and intermediate layers, and saturating said outer layer with a coolant liquid having a high heat ci vaporization, whereby upon exposure to intense external heat said external heat largely dissipated into the atmosphere by vaporizing said liquid, whereby the liquid and vapor are ver nted from penetrating to said body member.

2. 'L'ne method of shielding a member of the human body against intense external heat, cornprising placing over said body member an inner` layer of thermally insulating material substantially corresponding in shape to said body ber, then completely enclosing said inner layer with a layer of fluid-impermeable exible material of a shape corresponding to the shape of said inner layer, then completely enclosing said fluidimpermeable layer with a thick flexible liquidabsorbent glass-fiber fabric outer layer, the thickness of said outer layer exceeding the thickness o either of said inner and intermediate layers, and saturating said glass-fiber fabric layer with a coolant liquid having a high heat of vaporization, whereby upon exposure to intense external heat said external heat is largely dissipated into the atmosphere by vaporizing said liquid, and whereby the liquid and vapor are prevented from penetrating to said body member.

8. The method of shielding a human hand against intense external heat, comprising placing over said hand an inner layer of thermally insulating material substantially corresponding in shape to said hand, then completely enclosing said inner layer with a layer of fluid-impermeable ilexible material of a shape corresponding to the shape of said inner layer, then completely enclosing said fluid-impermeable layer with a thick flexible liquid-absorbent flexible outer layer, the thickness of said outer layer exceeding the thickness of either of said inner and intermediate layers, and saturating said outer layer with a coolant liquid having a high heat of vaporization, whereby upon exposure to intense external heat said external heat is largely dissipated into the atmosphere by vaporizing said liquid, and whereby the liquid and vapor are prevented from penetrating to said hand.

9. A glove for protecting a re-ghters hand by evaporative dissipation of intense external heat, said glove comprising a plurality of flexible layers conforming to the shape of a hand and arranged one over the other, and including a thermally insulating inner layer of low heat conductivity, an intermediate layer of fluid-impermeable material completely enclosing said inner layer, anda fire-resistant liquid-absorbent our layer of low heat conductivity completely enclosing said intermediate layer, said outer layer being of substantial thickness exceeding the thickness of either of said inner and intermediate layers, so as to retain a large quantity of a vaporizable coolant liquid having a high heat of vaporization for dissipating external heat when said liquid is heated beyond its boiling point and for maintaining the temperature of said outer layer at a point not exceeding the boiling point of said liquid until said liquid is completely vaporized, said intermediate and said inner layers being in cooperatlve relation with said outer layer to shield said hand from hot vapors and from conductive heat transfer.

10. A glove for protecting a re-ghters hand by evaporative dissipation of intense external heat,

`said glove comprising a plurality of nexible lay- REFERENCES CITED ers conforming to the shape of a hand and ar- Tha following ref emes are t d in ranged one over the other, and including a ther-Y me of this patent: er o moor the 4malLv insulating inner layer of lowheat coni ductivity, an intermediate layer of iiuidimper 5 VUNITED STATES PATENTS meable material completely enclosing said inner Number Name Date layer, and a tire-resistant liquid-absorbent outer 596,842 Borwell -1' Jan. 4, 1898 layer of glass fiber fabric completely enclosing 1,277,368 Blocksom Sept. 3, 1918 said intermediate layer, said outer layer being of 1,309,461 Cook July 8, 1919 substantial thickness exceeding the thickness of l0 1,730,763 Gerding Oct. 8, 1929 either of said inner and intermediate layers, so 2,222,782 Moses Nov. 26, 1940 as to retain a large quantity of a vaporizabie cool- 2,328,105 Strobino Aug. 31, 1943 ant liquid having a high heat of vaporization 2,381,542 Hyatt et al. Aug. 7, 1945 for dissipating external heat when said liquid is heated beyond its honing point and for mam- 15 FOREIGN PATENTS taining the temperature ot said outer layer at a Number Country Date point not exceeding the boiling point of said liq- 17,232 Gret Britain 1911 uid until said liquid is completely vaporized, said intermediate and said inner layers being in cooperative relation with said outer layer to shield 20 said hand trom hot vapors and from conductive heat transfer.

HEWITT COCHRAN. Executor of the Last Will and Testament of Margaret L. Ionides, Deceased. 25

PAUL A. SIPLE. 

